Revision: 24124
Author: [email protected]
Date: Mon Sep 22 14:40:59 2014 UTC
Log: Simplify synthetic roots creation in heap snapshot
The synthetic roots exist in every snapshot and there are no actual objects
corresponding to them (there was attempt to create some virtual objects to
reuse existing snapshot builder but it just complicated the things).
Previously synthetic root wouldn't have been added if it was empty. Current
implementation always adds all synthetic roots in the snapshot no matter if
they are empty or not.
BUG=None
LOG=N
[email protected], [email protected]
Review URL: https://codereview.chromium.org/590833002
https://code.google.com/p/v8/source/detail?r=24124
Modified:
/branches/bleeding_edge/src/heap-snapshot-generator-inl.h
/branches/bleeding_edge/src/heap-snapshot-generator.cc
/branches/bleeding_edge/src/heap-snapshot-generator.h
=======================================
--- /branches/bleeding_edge/src/heap-snapshot-generator-inl.h Mon Aug 4
11:34:54 2014 UTC
+++ /branches/bleeding_edge/src/heap-snapshot-generator-inl.h Mon Sep 22
14:40:59 2014 UTC
@@ -43,25 +43,6 @@
}
-SnapshotObjectId HeapObjectsMap::GetNthGcSubrootId(int delta) {
- return kGcRootsFirstSubrootId + delta * kObjectIdStep;
-}
-
-
-HeapObject* V8HeapExplorer::GetNthGcSubrootObject(int delta) {
- return reinterpret_cast<HeapObject*>(
- reinterpret_cast<char*>(kFirstGcSubrootObject) +
- delta * HeapObjectsMap::kObjectIdStep);
-}
-
-
-int V8HeapExplorer::GetGcSubrootOrder(HeapObject* subroot) {
- return static_cast<int>(
- (reinterpret_cast<char*>(subroot) -
- reinterpret_cast<char*>(kFirstGcSubrootObject)) /
- HeapObjectsMap::kObjectIdStep);
-}
-
} } // namespace v8::internal
#endif // V8_HEAP_SNAPSHOT_GENERATOR_INL_H_
=======================================
--- /branches/bleeding_edge/src/heap-snapshot-generator.cc Thu Sep 11
11:08:40 2014 UTC
+++ /branches/bleeding_edge/src/heap-snapshot-generator.cc Mon Sep 22
14:40:59 2014 UTC
@@ -188,7 +188,6 @@
uid_(uid),
root_index_(HeapEntry::kNoEntry),
gc_roots_index_(HeapEntry::kNoEntry),
- natives_root_index_(HeapEntry::kNoEntry),
max_snapshot_js_object_id_(0) {
STATIC_ASSERT(
sizeof(HeapGraphEdge) ==
@@ -217,6 +216,18 @@
}
+void HeapSnapshot::AddSyntheticRootEntries() {
+ AddRootEntry();
+ AddGcRootsEntry();
+ SnapshotObjectId id = HeapObjectsMap::kGcRootsFirstSubrootId;
+ for (int tag = 0; tag < VisitorSynchronization::kNumberOfSyncTags;
tag++) {
+ AddGcSubrootEntry(tag, id);
+ id += HeapObjectsMap::kObjectIdStep;
+ }
+ DCHECK(HeapObjectsMap::kFirstAvailableObjectId == id);
+}
+
+
HeapEntry* HeapSnapshot::AddRootEntry() {
DCHECK(root_index_ == HeapEntry::kNoEntry);
DCHECK(entries_.is_empty()); // Root entry must be the first one.
@@ -243,15 +254,11 @@
}
-HeapEntry* HeapSnapshot::AddGcSubrootEntry(int tag) {
+HeapEntry* HeapSnapshot::AddGcSubrootEntry(int tag, SnapshotObjectId id) {
DCHECK(gc_subroot_indexes_[tag] == HeapEntry::kNoEntry);
DCHECK(0 <= tag && tag < VisitorSynchronization::kNumberOfSyncTags);
- HeapEntry* entry = AddEntry(
- HeapEntry::kSynthetic,
- VisitorSynchronization::kTagNames[tag],
- HeapObjectsMap::GetNthGcSubrootId(tag),
- 0,
- 0);
+ HeapEntry* entry = AddEntry(HeapEntry::kSynthetic,
+ VisitorSynchronization::kTagNames[tag], id,
0, 0);
gc_subroot_indexes_[tag] = entry->index();
return entry;
}
@@ -769,20 +776,6 @@
entries_.Lookup(object, HeapEntriesMap::Hash(object), true);
cache_entry->value = const_cast<char*>(tag);
}
-
-
-HeapObject* const V8HeapExplorer::kInternalRootObject =
- reinterpret_cast<HeapObject*>(
- static_cast<intptr_t>(HeapObjectsMap::kInternalRootObjectId));
-HeapObject* const V8HeapExplorer::kGcRootsObject =
- reinterpret_cast<HeapObject*>(
- static_cast<intptr_t>(HeapObjectsMap::kGcRootsObjectId));
-HeapObject* const V8HeapExplorer::kFirstGcSubrootObject =
- reinterpret_cast<HeapObject*>(
- static_cast<intptr_t>(HeapObjectsMap::kGcRootsFirstSubrootId));
-HeapObject* const V8HeapExplorer::kLastGcSubrootObject =
- reinterpret_cast<HeapObject*>(
- static_cast<intptr_t>(HeapObjectsMap::kFirstAvailableObjectId));
V8HeapExplorer::V8HeapExplorer(
@@ -809,16 +802,7 @@
HeapEntry* V8HeapExplorer::AddEntry(HeapObject* object) {
- if (object == kInternalRootObject) {
- snapshot_->AddRootEntry();
- return snapshot_->root();
- } else if (object == kGcRootsObject) {
- HeapEntry* entry = snapshot_->AddGcRootsEntry();
- return entry;
- } else if (object >= kFirstGcSubrootObject && object <
kLastGcSubrootObject) {
- HeapEntry* entry =
snapshot_->AddGcSubrootEntry(GetGcSubrootOrder(object));
- return entry;
- } else if (object->IsJSFunction()) {
+ if (object->IsJSFunction()) {
JSFunction* func = JSFunction::cast(object);
SharedFunctionInfo* shared = func->shared();
const char* name = shared->bound() ? "native_bind" :
@@ -965,41 +949,6 @@
};
-class GcSubrootsEnumerator : public ObjectVisitor {
- public:
- GcSubrootsEnumerator(
- SnapshotFiller* filler, V8HeapExplorer* explorer)
- : filler_(filler),
- explorer_(explorer),
- previous_object_count_(0),
- object_count_(0) {
- }
- void VisitPointers(Object** start, Object** end) {
- object_count_ += end - start;
- }
- void Synchronize(VisitorSynchronization::SyncTag tag) {
- // Skip empty subroots.
- if (previous_object_count_ != object_count_) {
- previous_object_count_ = object_count_;
- filler_->AddEntry(V8HeapExplorer::GetNthGcSubrootObject(tag),
explorer_);
- }
- }
- private:
- SnapshotFiller* filler_;
- V8HeapExplorer* explorer_;
- intptr_t previous_object_count_;
- intptr_t object_count_;
-};
-
-
-void V8HeapExplorer::AddRootEntries(SnapshotFiller* filler) {
- filler->AddEntry(kInternalRootObject, this);
- filler->AddEntry(kGcRootsObject, this);
- GcSubrootsEnumerator enumerator(filler, this);
- heap_->IterateRoots(&enumerator, VISIT_ALL);
-}
-
-
const char* V8HeapExplorer::GetSystemEntryName(HeapObject* object) {
switch (object->map()->instance_type()) {
case MAP_TYPE:
@@ -1855,9 +1804,6 @@
void FillReferences(V8HeapExplorer* explorer) {
DCHECK(strong_references_.length() <= all_references_.length());
Builtins* builtins = heap_->isolate()->builtins();
- for (int i = 0; i < reference_tags_.length(); ++i) {
- explorer->SetGcRootsReference(reference_tags_[i].tag);
- }
int strong_index = 0, all_index = 0, tags_index = 0, builtin_index = 0;
while (all_index < all_references_.length()) {
bool is_strong = strong_index < strong_references_.length()
@@ -1899,11 +1845,16 @@
bool V8HeapExplorer::IterateAndExtractReferences(
SnapshotFiller* filler) {
filler_ = filler;
+
+ // Create references to the synthetic roots.
+ SetRootGcRootsReference();
+ for (int tag = 0; tag < VisitorSynchronization::kNumberOfSyncTags;
tag++) {
+ SetGcRootsReference(static_cast<VisitorSynchronization::SyncTag>(tag));
+ }
// Make sure builtin code objects get their builtin tags
// first. Otherwise a particular JSFunction object could set
// its custom name to a generic builtin.
- SetRootGcRootsReference();
RootsReferencesExtractor extractor(heap_);
heap_->IterateRoots(&extractor, VISIT_ONLY_STRONG);
extractor.SetCollectingAllReferences();
@@ -2619,6 +2570,8 @@
debug_heap->Verify();
#endif
+ snapshot_->AddSyntheticRootEntries();
+
if (!FillReferences()) return false;
snapshot_->FillChildren();
@@ -2659,7 +2612,6 @@
bool HeapSnapshotGenerator::FillReferences() {
SnapshotFiller filler(snapshot_, &entries_);
- v8_heap_explorer_.AddRootEntries(&filler);
return v8_heap_explorer_.IterateAndExtractReferences(&filler)
&& dom_explorer_.IterateAndExtractReferences(&filler);
}
=======================================
--- /branches/bleeding_edge/src/heap-snapshot-generator.h Thu Sep 11
11:08:40 2014 UTC
+++ /branches/bleeding_edge/src/heap-snapshot-generator.h Mon Sep 22
14:40:59 2014 UTC
@@ -100,7 +100,7 @@
Type type() { return static_cast<Type>(type_); }
const char* name() { return name_; }
void set_name(const char* name) { name_ = name; }
- inline SnapshotObjectId id() { return id_; }
+ SnapshotObjectId id() { return id_; }
size_t self_size() { return self_size_; }
unsigned trace_node_id() const { return trace_node_id_; }
INLINE(int index() const);
@@ -154,7 +154,6 @@
size_t RawSnapshotSize() const;
HeapEntry* root() { return &entries_[root_index_]; }
HeapEntry* gc_roots() { return &entries_[gc_roots_index_]; }
- HeapEntry* natives_root() { return &entries_[natives_root_index_]; }
HeapEntry* gc_subroot(int index) {
return &entries_[gc_subroot_indexes_[index]];
}
@@ -171,10 +170,7 @@
SnapshotObjectId id,
size_t size,
unsigned trace_node_id);
- HeapEntry* AddRootEntry();
- HeapEntry* AddGcRootsEntry();
- HeapEntry* AddGcSubrootEntry(int tag);
- HeapEntry* AddNativesRootEntry();
+ void AddSyntheticRootEntries();
HeapEntry* GetEntryById(SnapshotObjectId id);
List<HeapEntry*>* GetSortedEntriesList();
void FillChildren();
@@ -183,12 +179,15 @@
void PrintEntriesSize();
private:
+ HeapEntry* AddRootEntry();
+ HeapEntry* AddGcRootsEntry();
+ HeapEntry* AddGcSubrootEntry(int tag, SnapshotObjectId id);
+
HeapProfiler* profiler_;
const char* title_;
unsigned uid_;
int root_index_;
int gc_roots_index_;
- int natives_root_index_;
int gc_subroot_indexes_[VisitorSynchronization::kNumberOfSyncTags];
List<HeapEntry> entries_;
List<HeapGraphEdge> edges_;
@@ -223,12 +222,10 @@
size_t GetUsedMemorySize() const;
SnapshotObjectId GenerateId(v8::RetainedObjectInfo* info);
- static inline SnapshotObjectId GetNthGcSubrootId(int delta);
static const int kObjectIdStep = 2;
static const SnapshotObjectId kInternalRootObjectId;
static const SnapshotObjectId kGcRootsObjectId;
- static const SnapshotObjectId kNativesRootObjectId;
static const SnapshotObjectId kGcRootsFirstSubrootId;
static const SnapshotObjectId kFirstAvailableObjectId;
@@ -348,8 +345,6 @@
static String* GetConstructorName(JSObject* object);
- static HeapObject* const kInternalRootObject;
-
private:
typedef bool (V8HeapExplorer::*ExtractReferencesMethod)(int entry,
HeapObject*
object);
@@ -450,9 +445,6 @@
HeapEntry* GetEntry(Object* obj);
- static inline HeapObject* GetNthGcSubrootObject(int delta);
- static inline int GetGcSubrootOrder(HeapObject* subroot);
-
Heap* heap_;
HeapSnapshot* snapshot_;
StringsStorage* names_;
@@ -465,12 +457,7 @@
HeapObjectsSet weak_containers_;
v8::HeapProfiler::ObjectNameResolver* global_object_name_resolver_;
- static HeapObject* const kGcRootsObject;
- static HeapObject* const kFirstGcSubrootObject;
- static HeapObject* const kLastGcSubrootObject;
-
friend class IndexedReferencesExtractor;
- friend class GcSubrootsEnumerator;
friend class RootsReferencesExtractor;
DISALLOW_COPY_AND_ASSIGN(V8HeapExplorer);
--
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